1. Field of the Invention
This invention relates to a milky detergent composition for hard surfaces, and more particularly to a milky detergent composition for hard surfaces which does not irritate or damage the user's skin, has excellent foam producing ability (hereinafter referred to as "foamability") and detergency, gives a pleasant feel to the user's hands after washing, and is particularly suitable for use in cleansing tableware.
2. Description of the Background Art
In general, detergents suitable for use in washing items having hard surfaces such as tableware have as their principal object the removal of oil and/or grease smears. In most cases, users remove oil and grease smears by causing a detergent to foam by moving their hands or a sponge upon the hard surface. The foam serves to lessen the force required to remove the oil and/or grease smears and, generally, the volume of foam generated is a measure of the detergent's cleansability. Therefore, an important factor in such detergents is that they have high foamability. In conventional detergents for hard surfaces, an anionic surfactant such as an alkylbenzene-sulfonate, alpha-olefinsulfonate, alkylsulfate, paraffin-sulfonate or ethoxylated alkyl ether sulfate is used as the principal surfactant. Among these, sodium alkylbenzenesulfonates have been widely used as a base material having excellent cleansability. However, these surfactants suffer from a significant drawback: they have a strong delipidizing power on the user's skin that causes hand roughening. Accordingly, detergent compositions comprising, as a main detergent base material, a salt of a polyoxyethylene alkyl ether sulfuric ester, which is somewhat milder to the user's skin, have come to predominate in recent years. However, the action of even these later detergent compositions on the user's skin is short of wholly satisfactory even though they are milder than conventional detergent compositions.
On the other hand, it is known that an alkylglycoside, which is a nonionic saccharide-derived surfactant, is a low-irritative surfactant and, moreover, not only produces stable foam by itself but also acts as a foam stabilizer for other anionic surfactants. Japanese Patent Application Laid-Open No. 104625/1983 (corresponding to EP 70074) describes a foaming surfactant composition comprising an alkylglycoside and an anionic surfactant, and Japanese Patent Application Laid-Open No. 74999/1987 (corresponding to EP 216301 and U.S. Pat. No. 4,732,704) describes a liquid detergent composition for cleansing tableware, which comprises an alkylglycoside, an anionic surfactant and a fatty acid alkanolamide.
Further, Japanese Patent Application Laid-Open No. 164819/1990 (corresponding to EP 374702 and U.S. Pat. No. 5,025,069) describes a detergent composition which comprises an alkylglycoside, an anionic surfactant, an amine oxide and an ethylene oxide adduct of a nonionic surfactant which shows good foamability and detergency, and is in easily rinsed. In Japanese Patent Application Laid-Open No. 304198/1989, there is described a detergent for hard surfaces, which comprises an alkylglycoside and a fatty acid ester of a trihydric or still higher polyhydric alcohol which is excellent in foamability and detergency, and gives a good results after washing. All of these detergent compositions, however, are of the transparent solution type, and hence these references neither disclose nor suggest the present invention. Furthermore, while these reference compositions are superior in their various properties to conventional detergents comprising, as a main material, a polyoxyethylene alkyl ether, they are generally unsatisfactory, particularly in their feel given to the user's hands after washing and in their mildness towards delicate hands and skin.
There has thus been a demand for the development of a detergent composition for hard surfaces which is excellent in detergency and foamability, is low-irritative, and gives a pleasant feel to the user's hand skin after washing.